Cutter chain



Feb. 10, 1942. w w DARTNELL 2,272,692

CUTTER CHAIN Original Filed Aug. 1, 1938 J (an 272 .3 Fay/1 {6 423 12 60202 217; mm flZfiarZ/mZZ Patented Feb. 10, 194-2 CUTTER CHAIN William w. Dartnell, Claremont, N. in, assigncr'to. Sullivan Machinery Company, a corporationof Massachusetts Application August 1, 1938, 'Selial'No. 222,418 Renewed June '7, 1939 5 Claims.

This invention relates to cutter chains, and morev particularly to improvements in cutter chains especially, but not exclusively, adapted for use with coal cutting machines.

An object of this invention is to provide an improved mining machine cutter chain. An-

other object is to provide an improved cutter chain having improved means for holding the cutter bits in cutting position on the chain blocks. A further object is to provide an improved cutter bit of the double-ended, reversible cutter type which is extremely inexpensive and simple in design. Yet another object is to provide an improved cutter bit holder whereby a cutter bit is held in an improved manner in cutting position on a chain block. A further object is to provide an improved cutter bit holder pivotally mounted in a socket on a chain block and having adjusting means associated therewith whereby a cutter bit may be clamped in cutting position on the block in an improved manner. Still another object is to provide an improved cutter bit holder of the pivoted lever type. Other objects and advantages of the invention will, however, hereinafter more fully appear.

In the accompanying drawing there is shown for purposes of illustration one form which the invention may assume in practice.

In this drawing Fig. 1 is a side elevational view of a portion of the improved cutter chain.

Fig. 2 is a viewin central longitudinal vertical section, with portions in elevation, taken through the improved cutter chain shown in Fig. 1.

Fig. 3 is a fragmentary frontend elevational view of the cutter chain shown in Fig. 1, the view taken substantially on line 3-3 of Fig. 1.

Fig. 4 is a transverse sectional view taken substantially on line 4-4 of Fig. 1.

Fig. 5 is a detailsectional view taken substantially on line 5.5 of Fig. 2.

Fig. 6 is a detail view of the bit holder, showing the .same removed from the chain block socket and illustrating the method of forming the bit-receiving socket in the front holder face.

Fig. 7 is a cross sectional view taken on line 1-'l of Fig. 6. 1

Fig. 8 is a side elevational view of the improved cutter bit.

Fig. 9 is a cross sectional View taken on line 9-9 of Fig. 8.

Fig. 10 is a perspective view of the improved cutter bit.

Fig. 11 is a perspective view of the improved bitholder.

In this illustrative embodiment of the invention, there is shown a mining machine cutter chain comprising a series of chain blocks, one of which is indicated at l in Figs. 1 and 2, pivotally connected together by a series of strap links 2, the latter being pivotally connected at 3 to the chain blocks. Each chain block has a socket 4, herein preferably substantially rectangular in cross section and arranged perpendicular to the path of travel of the chain; and

formed on the-chain block at the front side of the socket. t is a laterally projecting lug 5, herein providing a front abutment and having a rounded rearward outwardly located abutment face 6 and a plane rearward inner abutment surface 1', the latter terminating at its inner end at the front wall of the chain block socket. Arranged with its shank 9 disposed within the chain block socket 4 is a rotatable holder l0, herein in the form of a lever pivoted at H on the chain block at the rear wall of the chain block socket. In thisconstruction, the rear side of the holder is transversely notched at I2, and

this notch engages a pivot pin i3 arranged transversely of the chain block at the rear side of the chain block socket, this pin being secured fixedly in place by the heading over of its ends at M within the recessed sides of the chain block. The holder has a head [5 projecting outwardly from the chain block socket, and the holder head is formed at its front side with an arcuate elliptical-shaped socket, herein preferably between V-shape and semi-elliptical in cross section. Threadedly secured within a threaded opening I! at the front side of the chain block is a set screw'lil, herein inclined inwardly and engaging the front side of the holder shank 9 in the manner shown in Fig, 2, so that when the set screw is tightened, the holder is swung about its pivot to move the holder into bit clamping position, in the manner to belater described.

The improved cutter bit is generaly indicated 19 and herein preferablyconsists of a forging and is in the form of a segment, of an oblate spheroid cut off by a plane parallel to the axis of the spheroid. In side elevation the cutter bit is in the form of a segment of a circle formed by a chord Whose intersections with the circle are spaced materially less than 180 and having a convex; back 26 and a plane front face 2! and terminating at its opposite ends in cutting points 22,. The bit is between V-shape and semi-elliptical shape in cross section and the front bit face 2i is elliptical in outline. The rear arcuate side or convex back of the bit is shaped to fit snugly in the holder socket I6, and the front plane face 21 of the bit is transversely notched at 23 midway between the cutting points. This bit notch 23 is engageable with the rounded abutment face 6 on the front abutment lug and the inner portion of the plane bit face is engageable with the plane abutment surface 1 on the lug in the manner shown in Figs. 1 and 2. When the cutter bit is inserted within the holder socket IS with the notch 23 of the bit engaging the lug abutment face 6 and the set screw is tightened, the holder lever is swung about its pivot to clamp the cutter bit firmly in position against the front lug, the lug projecting within the bit notch 23 locking the cutter bit against endwise displacement from the holder socket.

As clearly shown in Fig. 5, the front abutment lug and the holder head I5 are of a width no greater than the width of the cutter bit so that proper bit clearance is obtained. In this instance, the bit socket IS in the bit holder is formed by a circular milling cutter indicated by the reference character 24 in Fig. 6, and the cut ter bit in side elevation is of the same shape as a chordal segment of the milling cutter so that a snug fit of the cutter bit within the holder socket is made possible. It will be evident that if desired the lug abutment may be located at the rear side of the block socket and the holder arranged at the front side of the chain block so that, with such reversed arrangement of the parts, the cutter bit may be clamped firmly in position. The arrangement disclosed is, however, preferable from a practical standpoint.

The cutter bit I9 is herein of the reversible cutter type and may be reversed end for end with respect to the holder and lug so that when one point of the bit becomes dull, a sharp point may be presented to the work. Due to its inexpensive design, the cutter bit may be discarded when both points become worn.

As a result of this invention, it will be noted that an improved cutter chain is provided having an improved bit holder structure whereby the cutter bit is held in cutting position on a chain block in an improved manner. It will further be noted that by the provision of the improved front abutment lug and pivoted bit holder, the cutter bit may be firmly clamped in cutting position on the chain block. It will also be evident that by the provision of the improved bit shape, an improved cutter bit of an extremely inexpensive and rugged design is made possible. Other uses and advantages of the improved cutter chain will be clearly apparent to those skilled in the art.

While there is in this application specifically described one form which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illust-ration and that the invention may be modifled and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a cutter chain, a chain block having a socket and a front abutment, a rotatable bit holder mounted in said block socket for pivotal movement relative to the block and having a front bit-receiving socket, means mounted in said block for supporting said holder for pivotal movement while precluding bodily outward movement of said holder with respect to said block, a cutter bit received in said holder socket and engaging said front abutment, and means arranged at the front end of said chain block and engaging said holder for moving the latter about its pivot into clamping engagement with said cutter bit for clamping the latter against said front abutment, said cutter bit having its front face transversely notched and said front abutment having a rearward projection engaging said notch for locking the cutter bit against longitudinal displacement from said holder socket.

2. In a cutter chain, a chain block having a socket and a front abutment, a pivoted bit holder lever mounted on said block for pivotal movement relative thereto and having a shank projecting inwardly within said block socket and an outwardly projecting head provided with a front bit-receiving socket, means permanently mounted in said block and distinct from the rear wall of said block socket for supporting said holder lever for pivotal movement, a cutter bit received in said holder socket and engaging said front abutment, and means arranged at the front end of said chain block and engaging one end of said holder lever shank for moving the holder lever about its pivot into clamping engagement with said bit for clamping the latter against said front abutment, said cutter bit having its front face transversely notched and said front abutment having a rearward projection engaging said notch for locking the cutter bit against longitudinal displacement from said holder head socket.

3. In a cutter chain, a chain block having a socket and a front abutment, a rotatable bit holder mounted in said block socket for pivotal movement relative to the block and having a front bit-receiving socket, means mounted in said block for supporting said holder for pivotal movement while precluding bodily outward movement of said holder with respect to said block, a cutter bit received in said holder socket and engaging said front abutment, and means arranged at the front end of said chain block and engaging said holder for moving the latter about its pivot into clamping engagement with said cutter bit for clamping the latter against said front abutment, said cutter bit having its front face transversely notched and said front abutment having a rearward projection engaging said notch for locking the cutter bit against longitudinal displacement from said holder socket and said abutment having a rearward plane surface with which the inner portion of the front face of the cutter bit abuts.

4. In a cutter chain, a chain block having a socket and a front abutment, a pivoted bit holder lever mounted on said block for pivotal movement relative thereto and having a shank projecting inwardly within said block socket and an outwardly projecting head provided with a front bit-receiving socket, a pivot pin mounted in said block and with which said holder lever is pivotally engaged, a cutter bit received in said holder head socket and engaging said front abutment, and means arranged at the front end of said chain block and engaging one end of said holder lever shank for moving the holder lever about its pivot into clamping engagement with said bit for clamping the latter against said front abutment, said cutter bit having its front face transversely notched and said front abutment having a rearward projection engaging said notch for locking the cutter bit against longitudinal displacement from said holder head socket, and said abutment having a rearward plane surface with which the inner portion of the front face of the cutter bit abuts.

5. In a cutter chain, the combination comprising a chain block having a socket and a front abutment, a bit holder lever mounted on said chain block for pivotal movement relative thereto and having a shank projecting inwardly Within said block socket and an outwardly projecting head, a transverse pivot pin mounted permanently in said block and providing a pivotal mounting for said holder lever, said lever 

